I would not expect Greyhound in Jasper to have a bike box. Your best bet is a local bike store. I shipped a recumbent with Greyhound once. They lost the bike in their receiving depot for 10 days. Thankfully it was the return part of the trip. The bike had been professionally packed and it suffer some minor damage. Since then, I always ship UPS or Fedex. Theey have yet to lose a bike and the bike always arrives at the destination on time
Enjoy your trip. The views are awesome